Admissibility of evidence in arbitration proceedings

11 July 2007

Emma Morales

Under Spanish law, evidence can only be used in arbitration if it is obtained in compliance with LEC rules (the Spanish Civil Procedural Law). In international disputes, IBA Rules on the “Taking of Evidence in International Commercial Arbitration” may also be applied.

When considering what evidence is required, arbitrators should focus on the areas which are in dispute between the parties. Arbitrators should also inform the parties about the rules on obtaining evidence, as the parties may seek an “annulment” of the award where evidence has been unlawfully obtained.

Arbitrators must bear in mind the fact that the amount of evidence required should not place an excessive financial burden on the parties. To the extent that evidence is not forthcoming, arbitrators may apply to the Court to compel production of evidence.

Of the various types of evidence, it is expert reports which are most controversial. Indeed, although arbitrators are not allowed to delegate their functions, they usually rely heavily upon expert reports when they make their ultimate decision. For this reason and in order to avoid the unenforceability of the evidence, the appointment of the expert and the importance of the report have to be clear at the outset.

Expert evidence

Arbitrators are entitled to ask the parties to provide the expert with all the information and documentation the expert may require, although arbitrators can decide on the relevance or appropriateness of the documents required.

After the submission of their reports, experts are generally asked to attend the hearing.

Parties may also submit expert reports when they serve their statements of case.

The law is quite flexible upon the exhibits which experts may wish to include/rely upon:

  • The arbitrators will make a decision about the admissibility of the exhibits which they find suitable to support their arguments.

  • Parties are not compelled to provide any exhibits with their statements of case.

  • Parties may even mention in their statements of case the exhibits they intend to provide after service of their statements of case.

Arbitrators must show the evidence upon which they rely to reach their decision to both parties in order to give them the possibility to "test" the evidence.